Accumulator-type injection systems for injecting fuel from an accumulator (rail) into a combustion chamber of an internal combustion engine using injectors are known in different embodiments. Accumulator-type injection systems have previously been constructed in such a way that the injectors are arranged outside the engine block or cylinder head and the feedlines from the rail to the injector run on the outside. As the fuel is under high pressure in the rail and in the feedlines to the injector in the accumulator-type injection systems, leakages sometimes occur, in particular at the connections between the individual components. On the one hand, this escaping fuel pollutes the environment if it drips out of the engine compartment, and on the other hand the risk of fire in the engine compartment, in which there may be relatively high temperatures, is thus increased.
Furthermore, hitherto it has not been possible in accumulator-type injection systems to sense in particular small leaks at which only small amounts of fuel penetrate to the outside. Large leaks can be determined, for example, by means of differences in the pressure in the rail. However, relatively small fuel leaks frequently evaporate at the point where they escape so that they can only be detected with difficulty, or cannot be detected at all.